Changes And Significance Of Th17/IL-17 In Peripheral Blood Of Asthmatic Children

Object:To observe the levels of Th17/IL-17 in peripheral blood of asthmatic children and study its role in pathogenesis of asthma.Methods:In this research,we take children with asthma as research subject.According to the severity of asthma,they were divided into 3 groups:slight asthmatic children(the slight group,n=29),moderate asthmatic children(the moderate group,n=16),severe asthmatic children(the severe group,n=20).The healthy children(the healthy control group,n=15) served as control.We isolated peripheral blood mononuclear cells (PBMC), and then detected the percentage of Th2, Th1 and Th17 of PMBC by flow cytometry (FCM).The levels of IL-17 in plasma were tested by Enzyme-linked Immuno Sorbent Assay (ELISA).Results:Thl cells with negative CD8 and positive CD3 secret IFN-γ.Compared with the healthy control group,the levels of Thl cells in the asthma groups all decreased[respectively (12.41±4.86)%vs (16.40±5.71)%, p=0.018<0.05; (12.27±5.83)%vs(16.40±5.71)%, p=0.030<0.05; (11.21±4.73)%vs(16.40±5.71)%, p= 0.005<0.01],with statistical significances,while there was no statistical meaning with regard to the multiple comparison among the three asthma groups.(2)Th2 cells with negative CD8 and positive CD3 secret IL-4.Compared with the healthy group,the level of Th2 cells in the asthma groups increased, and the difference was statistically significant (2.69±1.75)%vs (1.64±0.74)%, p<0.05].There was a statistically significant difference between the healthy control group and the severe group.We compared the slight group and the moderate group with the healthy control group respectively,the mean number of Th2 cells raised but no statistical significance was obtained[(2.51±1.73)%vs (1.64±0.74)%, p=0.094>0.05; (2.75±2.00)%vs (1.64±0.74)%, p=0.061>0.05].There were no significant differences among the childhood asthma groups.(3)Th17 cells with negative CD8 and positive CD3 secret IL-17.The levels of Th17 cells in the asthma groups were significantly higher than those of the healthy control group,and there were statistic significances[(2.10±1.37) %vs (1.30±0.53)%, p<0.05].The comparison were made between the severe group and the healthy control group,and showed statistic significance[(2.54±1.45)%vs (1.30±0.53)%, p<0.01]. Comparing the slight group and moderate group with the healthy group,we found that the mean number of Th17 cells rised but with no statistical significance.[respectively (1.77±1.16)%vs (1.30±0.53)%, p=0.239; (2.14±1.54)%vs(1.30±0.53)%,p=0.064].The difference between severe group and slight group showed statistical significance[(2.54±1.45)%vs (1.77±1.16)%, p=0.036<0.05],while no difference was found when comparing the Th17 number of the moderate group with the other two asthma groups. (4)Compared with the healthy control group,IL-17 levels in plasma increased in the asthma groups [respectively[(17.91±8.36)%vs (8.47±4.51)%, p<0.05], and the differences were statistically significant.Comparing the severe group and the moderate group with the control healthy group, there were statistic significances[(25.34±14.19)%vs (8.47±4.51)%, p<0.01; (16.40±8.73)% vs (8.47±4.51)%, p<0.05].The levels of IL-17 raised both in the slight group and the healthy control group [(13.62±9.25)%vs (8.47±4.51)%, p=0.111], but the differences were not statistically significant.The severe group showed elevated levels of IL-17 in comparison with the other two asthma groups[respectively, (25.34±14.19)%vs (16.40±8.73)%, p= 0.010<0.05; (25.34±14.19)%vs(13.62±9.25)%,p<0.01]. The differences had statistical significance,while no difference was obtained statistically significant in comparison of the mild group and the moderate group.(5)The comparison of the percentage of IL-17 between the EA group and the NEA group showed no statistical significance[(2.52±1.41)% vs(1.95±1.34)%,p>0.05].(6)The comparison of the levels of IL-17 between the EA group and the NEA group showed statistical significance[(22.84±11.37)pg/ml, (16.16±11.68)pg/ml, p<0.05)].(7)The percentage of PBMC in the asthma groups were positively correlated with NEU and EOS in peripheral blood (r=0.803, p<0.0001;r=0.261, p=0.020),but uncorrelated with LYM(r=0.018, p=0.873).(8)The level of IL-17 in asthma group were positively correlated with NEU in peripheral blood(r=0.733, p<0.0001;r=0.226, p=0.044), but uncorrelated with LYM (r=0.059, p=0.603).(9)The level of IL-17 in asthma group were positively correlated with the percentage of TH17 cells in PBMC (r=0.810, p<0.0001).Conclusion:Compared with healthy subject, the percentage of CD3+CD8-IL-17+Th17 cells in PBMC increased in asthmatic children,and had astatistical significance.Th17 immunity involved in the pathogenesis of asthma in children by systemic inflammation response syndrome.2.The percentage of CD3+CD8-IL-17+Th17 cells in PBMC and the level of IL-17 in plasma of asthmatic children all increased and were positively correlated with the severity of asthma. Suggesting that Th17/IL-17 immunity involved in the pathophysiological process of acute exacerbation of asthma as promoting factor.3.Th17/IL-17 may not only involved in neutrophil-mediated inflammation of asthma, but also related to eosinophilic inflammation, providing an important supplement inflammatory mechanisms of asthma.4.EA and NEA's classification is also applicable to children with asthma, and we need further study on different types of inflammatory to explore suitable treatment. 5.The levels of IL-17 expression in plasma and the severity of asthma have a significant relationship, suggesting that IL-17 can be used as activity index of asthma in children,and also is expected to provide new targets for asthma treatment.